The invention concerns a treatment agent for ophthalmology and use thereof in ophthalmological process as for reapplying a retina, for permanent tamponade and as a vitreous humor substitute.
Liquid perfluorocarbons are suitable as a treatment liquid for reapplying a detached retina to the chorioid of the eye, by unfolding or unrolling of the retina (L. Clark, EP No 0 089 232; H. Meinert, European patent application No. 91 120184.6).
Because liquid perfluorocarbons have a suitably high density (higher than 1.6 g/cm.sup.3) and an extremely low surface tension (lower than 25.times.10.sup.-5 N/cm or 25 dyn/cm), they are suitable for unfolding or unrolling a detached retina and pressing it back into place. The low surface tension advantageously prevents the treatment liquid from passing behind the retina if it has one or more tears.
Perfluorocarbons are chemically and physiologically inert compounds, if they are in a state of high purity.
The perfluorocarbon liquids which are to be used for reapplying a detached retina must be absolutely non-toxic. Accordingly such perfluorocarbons may not contain any impurities at C-H-bonds, which by way of intramolecular HF-separation result in the formation of fluorolefinic double bonds. That means in exact terms that the perfluorocarbon liquids to be used may not contain any impurity components which also contain --CHF-groups besides --CF.sub.2 -groups in a molecule because that gives rise to HF-separation and linked thereon toxicity, as follows: EQU --CHF--CF.sub.2 --, --CF.dbd.CF--+HF
It is also known that the perfluorocarbon liquids which are used for unfolding a detached retina, after a residence time of some days, have to be removed from the eye and substituted by another medium. That vitreous humor substitute such as for example silicone oil is used for a prolonged tamponade effect for the reason that the high density of the perfluorocarbon liquids would be against long-term tamponade (M. E. Hammer et al in: H. Mackenzie Freenam, F. I. Tolentino: PVR, Springer-Verlag 1988).